End detector for knitting machines



Oct. 6, 1936. WACHSMAN 2,056,307

END DETECTOR 'FOR KNITTING MACHINES Filed NOV. 14, 1955 2 Sheets-Sheet l \TaMZ mdmmn/ IN V EN TOR.

y f fi N X Oct. 6, 1936. J. WACHSMAN 2,056,307

END DETECTOR FOR KNITTING MACHINES Filed Nov. 14, 1935 2 Sheets-Sheet 2 5 15.1 Ema 42 /4 4a 4 37 LA, J0

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Patented Oct. 6, 1936 2,056,307 END DETECTOR FOR KNITTING MACHINES Jacob Wachsman, Brooklyn, N. Y.

' Application November 14, 1935, Serial No. 49,648

1 Claim; (Cl. 66-163) UNITED s Arss PATENT OFFICE This invention relates to improvements in end detectors forknittingmachines, that is devices which are controlled by the travelling thread and are arranged to-close an electric circuit'wlien the thread breaks or runs out.

The broad object of the invention is toprovide an end detector device which shall be especially ancient and adapted for operation with very fine yarns or threads. Another object of the invention isto construct the end detector in a manner to make it especially well adapted for efficient operation inthat it includes construction features for eliminating failure of operause due to vibration by the knitting machine and.

' it also includes features which prevents short circuiting.

The invention is embodied in an end detector device arranged and constructed as hereinafter set forth and as illustrated in the accompanying drawings in which the end detector is shown mounted for operation upon a knitting machine of the type disclosed in my U. S. Patent No. 1,775,298, though it is not limitedto that type or machine. In the said drawings b Fig. l is a diagrammatic view of a portion of acircular knitting machine with my invention applied. h

Fig. 2 is a sideview of one form of my improved end detector.

' "Fig". 3 is an end view thereof;

Fig. 4 is an end view of another form of my end detector.

Fig. 5 is a side view of Figure 4.

Referring to Figure l, the numeral 6 represents a rotatable central shaft or post of the knitting machine which is mounted on a suitable bearing 1 supported from the bed 8. The shaft is rotated in any suitable manner, not shown, and carries a series of radial arms 9 which support the spindles for the spools l0. Above the arms 9 is another series of radial arms II which carry the first end detectors E2, the detailed construction of which is to be explained in detail hereafter.

At the top of the post there is a third series of arms I3 which support circuit closers I 4 which are shown diagrammatically and which may be of the construction shown in my U. S. Patent No. 2,013,529. The circuit closers l4 function to close the circuit when there is a knot or obstruction on the yarn or when the yarn breaks. It should be noted that there usually is a considerable distance between the end detectors l2 and the circuit closers I4.

Beneath the arms 9 is a disk I5 from which,

preferably at diametrically oppositepoints, radiate contact fingers or brushes H5 which are insulated from the disk l5 as at H and. to which the insulated circuit terminals: of the circuit closers l2 and M are electrically connected in a 5' well known manner as indicated by wires l8. The wires are shown by dot and dash lines to distinguish them from the lines of the yarn. Mounted on fixed supports 29 through insulating connections 2! is a contact ring 22 with which the fingers it have a wiping contact. The ring 22 being stationary and the fingers 96 being rotatable rub along the under edge, of the ring and assist in maintaining its surface bright and clean for good electrical contact. 15

in turnactuates a stop mechanism, not shown, 25

to stop the machine. This is, well known in the art. In operation the yarn or thread 26 is passed from the spools l9 upwards through the end detectors l2, thence up ,over the knot detector's l lp thence down through suitable guides 50 21, thence downthrough the detectors 24 to the knitting mechanism, not shown. x V

I will now describe my improved end detector which is embodied in a very substantial construction to insure rigidity against vibration. At the 35 same time the circuit closing elements are constructed in a manner to make the device very sensitive and adapted for operation with very fine yarns.

- Referring to Figures 2 and 3 the end detector 40 consists of a very substantial rectangularly bent bracket consisting of a horizontal supporting branch 30 and a vertical guiding branch 3| having two parallel inclined guides 32, 32 provided with eyelets 33 in substantial alinement with an 45 eyelet 34 in the branch 39. The latter has holes 35 for attachment to the knitting machine.

On top of the branch 30 there is mounted a contact box 36 which is completely closed so as to enclose a leaf spring contact 3')! and the con- 50 tacting heel 38 of a detector lever 39 pivoted in the sides of said box at 49. The detector lever 39 is in the form of a very fine thin steel wire having a hook 4| at its lower end adapted to swing between the guides 32 as shown. It will readily be understood from the drawings that because of the very short heel as compared to the great length of the wire 39, the latter tends to assume a vertical position under the influence of gravity. On top of the contact box there is mounted a circuit terminal 42 suitably insulated as at 43. The terminal is secured at two places 44 and 45 and cannot turn. At 45 the terminal 42 is in electrical contact with the spring 31. The box is secured by a rivet 46 and is prevented from turning by having lips 41 engaging the sides of the bracket 30. Hence it will be noted that this construction is of extreme rigidity, eliminates the loosening of parts due to vibration and prevents short circuiting. A tension device 48 may be mounted on a lateral branch 49. V

In operation the thread 23 is passed through the eyelets 33 and 35, the hook 4| of the wire 39 being swung in behind the thread. When the thread runs out, the wire 39 swings forward, the heel 38 contacts with the spring contact 31 and the circuit is closed.

The device is extremely sensitive. Although the wire lever 39 is very much heavier than the heel 38 (see also Fig. 4) it is sufficiently delicate and sensitive so' as to give with the thread. It is understood of course by anyone familiar with the operation of a knitting machine that the thread is not pulled through the machine in an exact straight line but that the operation is jumpy so to speak and that at times the wire hook 4| is pulled back into the position shown in the drawing and at times the wire swings slightly forwardly. In other words there is a constant rub of the thread against the wire hook, hence the latter must be thin enough and sensitive enough to prevent uninterrupted operation so long as the thread remains. When, however, the thread breaks the wire lever must instantly swing into circuit closing position. The device-illustrated and described fulfills these demands to an extraordinary high degree of perfection.

Figures 4 and 5 illustrate an end detector em bodying the same features as above described but arranged for placement in knitting machines where the detector in Figure 2 cannot be used to advantage. Similar parts in Figures 4 and 5 are-lettered with the same reference characters as those in Figure 2. In this case there is provided a vertically disposed supporting bracket 50 having three lateral guide arms 5| provided with eyelets 52. The contact box 36 is secured to the bracket 50 back of the thread which passes through the eyelets 52. The contact terminal 53 is secured to the box and extends to one side of the bracket a considerable distance at right angles. The tension device 48 is mounted on the contact terminal. The contact wire 54 is pivoted in the box at 40 and has a heel 55 adapted to contact the spring terminal 31 to which the fixed terminal 53 is electrically connected by a rivet 56. The upper end of the wire lever 54 has a porcelain covered arm 51 which crosses the path of the yarn 26 which is passed through the three alined eyelets 52. When the thread runs out the wire lever falls outward under the influence of gravity and the circuit is closed between the heel 55 and the spring 31. In Figure 2 the yarn may be led over the tension device before passing through the eyelets 33. In Figure 4 the thread may be passed around the tension device before passing through the two upper eyelets 52.

In both cases it will be noted that the eyelets are grouped. One group containing one eyelet and the other group containing two eyelets. This arrangement permits the device to be used with or without tension as is obvious.

I claim:

A stop mechanism of the character described comprising a bracket bent at right angles to form a horizontal and a vertical depending arm, the latter having its lower free end bent at an acute angle in the direction of the said horizontal arm and forming a thread guiding arm, a second thread guiding arm secured to the said vertical bracket arm in parallel relation to the said first named guiding arm, eyelets in the free ends of said guiding arms, a closed contact box secured in non-turnable relation on top of said horizontal bracket arm, an insulated contact spring in said box, a gravity actuated lever pivoted in said box to one side thereof and having a contact heel within the box adapted to make contact with the said contact spring, the lower end of said gravity lever being bent at right angle and adapted to engage a thread passing through the said eyelets between the same to keep the said contact heel in circuit open position within the box, a tension device secured to the said vertical bracket arm above the said two thread guiding arms and an eyelet in the said horizontal bracket arm in substantial alinement with the said tension device and the said two first mentioned eyelets.

JACOB WACHSMAN. 

